The present invention relates to a mechanical press, and particularly to a mechanical press suitable for forming parts by cold extrusion, punching and drawing with high precision.
A mechanical press having a reciprocating slider connected, through rods, to one end of an oscillating plate oscillating around a driving shaft is disclosed in, for example, Japanese Patent Unexamined Publication No. 60-210398.
Since the oscillating plate is carried by a movable shaft only, such a swash plate type mechanical press has a long span between an axis of the movable shaft and the force point subjected to a work load during press. A rigidity of the oscillating plate of the mechanical press thus becomes low, and then work parts with high precision cannot be obtained.
In addition, a cross spider type universal joint serves not only as a joint, but also as a lock pin mechanism for preventing the oscillating plate from rotating together with the driving shaft. Therefore, the mechanical press has a low rigidity and durability, particularly, to a larger driving torque generated during the operation of the press. Further, since the universal joint itself is a nonuniform joint, rotation cannot be stably transmitted, and then it is difficult to produce products with high precision.